Multi-purpose utility structure



June 21, 1966 P. F. CUMMINS MULTI-PURPOSE UTILITY STRUCTURE 5 Sheets-Sheet 1 Filed Feb. 21, 1964 INVENTOR PHIL F. CUMMINS 5 Sheets-Sheet 2 Filed Feb. 21, 1964 PHIL F. CUMMINS ATTORNEY June 21, 1966 P. F. CUMMINS 3,256,896

MULTI-PURPOSE UTILITY STRUCTURE Filed Feb. 21, 1964 5 Sheets-Sheet 3 i w 7 u 5-760 PHIL F CUMMINS INVENTOR.

ATTORNEY June 21, 1966 P. F. CUMMINS 3,255,896

MULTI-PURPOSE UTILITY STRUCTURE Filed Feb. 21, 1964 5 Sheets-Sheet 4 NVENTO PHIL F. CUMMINS June 21, 1966 Filed Feb. 21, 1964 P. F. CUMMINS MULTI-PURPOSE UTILITY STRUCTURE 5 Sheets-Sheet 5 INVENTOR PHIL F. CUMMINS combat conditions.

3,256,896 MULTl-PURPOS- UTELITY STRUCTURE Phil F. Cummins, Fort Worth, Tex., assignor to Sentinel Products Corporation, Fort Worth, Tex., of Texas Filed Feb. 21, 1964, Ser. No. 346,489 4 Claims. (Cl. 135-4) The present invention relates generally to portable shelters, and more particularly to a transportable, lightweight, plicated shelter that is self-contained, readily erectable, autopacking, and in general serves as an all purpose utility structure.

Heretofore and up to the present time various portable shelter constructions have been evolved to protect man and his possessions from ambient or environmental conditions. Such shelters were basically of three types, i.e.,

the fabric covered type, inflatable type, or pre-fabricated type.

Present shelters ofall three of these types have certain characteristics which are deleterious to their utility. These reside primarily in a disproportionate bulk and weight of such structures in their collapsed or transportable state. Excessive time and effort required to effect disposition of the covering or fabric and subsequent erection of supporting center poles, eave poles, stakes and guide lines are additional factors which are detrimental in character to the present state-of-the-art. Obviously, as the size of the structure increases, the complexity of such a shelter and consequent difiiculties encountered during erection increases by a disproportionate factor. As a consequence, many instructional manuals are prepared relating to the erection of such structures. For example, Department of the Armys Field Manual FM20-15, dated 1956, sets forth statistics regarding various military shelters presently employed. Of the shelters reviewed, only one was considered to be commensurate in erected size to the preferred embodiment of the present invention.

This structures statistics are delineated on page 31, under section five, General Purpose Tent, Medium. This section indicates that such shelters weigh 255 pounds in the collapsed state and that this figure is further augmented by the addition of poles and pins which result in an additional 200 pounds, effecting a total unit weight of 455 pounds. This structure, when erected, is 16 feet wide, 33 feet long, has a wall height of 5 feet 6 inches, and a pitch of 4 feet 6 inches. It requires four well trained personnel approximately forty minutes to erect this shelter, if given relatively ideal conditions.

Another example, taken from the referenced manual, is the Maintenance Shelter presentely employed by the military. This shelter weighs 1255 pounds and employs a metal frame, and ideally requires seventy-five minutes for ten men to erect.

Obviously, these shelters, due to their complex construction cannot be erected efficiently at night without benefit of light, nor can such shelters be erected silently. Such silent erection would be extremely advantageous under Furthermore, these shelters are extremely diflicult to erect upon either high or low density terrain, such as snow or ice, and consequently demand considerable special preparation to allow disposition of supporting and retaining components in these areas. Such special preparation is a major handicap, since the trend in military operations is toward the more remote areas of the world. Further accumulation of snow or moisture on these structures is of general concern because they are intrinsically weak and subject to collapse when loaded. These shelters require considerable time to repackage on striking. This is necessary to reduce the structure to its portable state and to avoid the loss of any ofits components. Inmany instances this disassembly a corporation United States Patent O requires more time than does erection. Obviously, in military operations, it is just as important to be able to strike camp rapidly as it is for quick erection.

Another obstacle in the efiicient employment of conventional shelter structures is that only a portion of their volume is fully functional. Shelters of the above type have a gable-like front elevation and side walls which are considerably shorter than the average man, thereby partially restricting movement within the shelter. This remaining volume is further limited in its usefulness by the employment of center poles, etc.

Some state-of-the-art shelters are rapidly erectable. These shelters generally are of the inflatable type, but have serious, readily apparent limitations as does any object that employs a captivated or pressurized substance such as air or gas for its rigidity and operability.

The present invention obviates all of the above problems and embodies a longitudinally expandable shelter comprising a plurality of cooperative structural rib members, having a suitable cover member afiixed to the interior thereof, and interconnected by a suitable system of bar linkages. A typical shelter, according to the present invention, is expandable from its compact, transportable configuration of eleven inches to a length of 40 feet in one minute and by asingle individual. The foregoing structure weighs in its entirety approximately 240 pounds. Because of such structures simplicity, i.e, the absence of poles, stakes and guy lines, it may be erected silently and at night, without the benefit of light and can be pitched on either normal, high or low density surface media. The shelter has an exceptionally high structural integrity, as exemplified by one embodiment incorporating a plurality of aluminum alloy ribs, which ribs will each support eight hundred pounds of static weight. Further, the structure of the present invention, upon plication, forms its own protective covering. This is due to the novel position and folding-in of the fabric in relation to the structural rib members, and to the ability of the linkage system to allow each rib to affay (i.e., come together so as to fit or join closely) its adjacent ribs when such system is in the collapsed state, thereby creating a substantially continuous composite wall which protects another shelter as a surgery unit, and other shelters as wards. If ten, forty-by-eight-by-eight foot structures were employed in such a configuration, it would require only ten men to erect the entire field hospital, and would require only one minute for actual shelter erection. Further, the structural capabilities of the shelter, plus the facility with which the entire interior thereof may be utilized is extremely important when litter patients must be accommodated. These litter patients may be supported in tiers from the ribs, thus leaving the center area unrestricted. Another extremely useful feature of such structures resides in the fabric/rib relationship, which allows a secondary cover or sock to be laid over the ribs, thus providing a dead air space therebetween. This dead air space may be filled with insulations of various types if desired.

The actual size and configuration of the structure is practically unlimited and possesses a great latitude of growth potential. This is best illustrated by conceivably laying'such a plicated structure within its associated container upon a low-boy trailer of some forty feet in length and eight feet in width. The container could easily exceed eight feet in depth, thereby permitting approximately 300 feet of expandable structure to be transported. In this configuration the plicated shelter within its container may be easily raised upon one side of the trailer with the assistance of hydraulic, pneumatic or mechanical apparatus. The container and structure is then lowered mechanically to the ground or any desired level. Here again auxiliary assist systems would push the shelter from the container. This action is facilitated, as herein stated, by employment of small wheels upon or within the rib members, thus expanding the shelter to its full 300-foot length, 40-foot width and 8-foot height. This configuration would have 12,000 square feet of floor space and is fully portable. The shelters ribs would necessarily be reinforced to withstand the loading of the unsupported span of the roof, however, the interior would still remain fully functional. Further, portions of the bed of the trailer, i.e., the area within the center of the arch formed by the container, may be utilized to transport supplies, portable generators, heating or cooling apparatus, etc. It is obvious a structure of this type would be of great assistance for disaster relief and the like and may be readily air lifted.

Therefore it is the salient object of the present invention to provide a lightweight, readily erectable, all purpose utility structure having an expansion ratio of substantially forty-to-one, and comprising a series of structural ribs in combination with a fabric and incorporating an articulated system of expandable linkages.

Another object is to provide a structure in which the fabric is attached to the inside of the ribs, thereby allowing such ribs to affay and form a composite protective shield when in a collapsed state.

In the figures:

FIGURE 1 illustrates pictorially the configuration and geometry of the prefered embodiment;

FIGURE 2 is an elevational view of a portion of a typical rib member illustrating the manner in which the fabric may be attached, and one means employed to achieve pivotal connection of the extending linkages;

FIGURE 3 is an elevational view partially in section illustrating the .pivotal connection of the bars of a linkage employed in the invention;

FIGURE 4 is apartial elevational view of a rib member illustrating a sleeve element in cross-section slidably received thereupon;

FIGURE 5 is a detail plan view of the sleeve element of FIGURE 4 specifically illustrating the bushing therewithin;

FIGURE 6 is a partial elevational view of a spacer employed at either extremity of the shelter for assuring proper alignment of the end bar linkages;

FIGURE 7 is a pictorial representation illustrative of an embodiment of the present invention having foldable sidewalls;

FIGURE 8 is a partial elevational sectional view of a means for locking the side walls of the embodiment of FIGURE 7;

FIGURE 9 is a cross-sectional plan view of the locking means taken along the line VIII-VIII of FIGURE 7;

FIGURE 10 is a perspective view of one embodiment of the present invention mounted upon a vehicle;

FIGURE 11 pictorially illustrates another embodiment of the present invention wherein a portable shelter according to the present invention'is employed to protect w an aircraft.

FIGURE 1 shows a preferred embodiment of the present invention, wherein a shelter 10 comprises a plurality of channel shaped rib members 12 constructed of a suitable lightweight, relatively high strength material such as various aluminum alloys or stainless steels. Rib members 12 are, in the preferred embodiment, rectangular in cross-section for purposes of strength, however, it is to be understood that any suitable shape may be employed to meet specific requirements or conditions. Rib members 12 are equidistantly disposed longitudinally in a column and are interconnected on diametrically opposed sides by a system of cooperative expandable bar linkages 14.

This system of ribs and linkages is hereinafter related in geometrical terms. Only that section of the system pertaining to any two ribs 12 and the cooperative interconnecting linkages 14 on one side thereof will be described, both statically and dynamically, for purposes of orientation. Such description is possible for all such ribs and linkages are substantially identical, physically and functionally, with only very minor variations at either extremity of the column which variations will be hereinafter described in detail.

As hereinabove stated rib members 12 are disposed in an equidistant longitudinal column, thus creating a series of imaginary parallel planes, two of which are designated 16 and 18 respectively. Imaginary planes 16 and 18 are, as stated, interconnected by a linkage system represented geometrically by imaginary lines 20 and 22. Imaginary line 22 is pivotally affixed to point 24 in the lower extremity of plane 16, and is also pivotally afiixed at its opposite extremity to a vertically movable point 26 located within the upper extremity of plane 18. The other imaginary line 20 between planes 16 and 18 is substantially identical, but opposite in sense, to the first. However it is positioned on a path which converges with plane 20 is pivotally afiixed at-one extremity to point 28, which point corresponding to point 24 in plane 16. It in turn is pivotally aflixed at its upper extremity to a second vertically movable point 30 within plane 16, corresponding to point 26 in plane 13. In this configuration lines 20 and 22 cross diagonally at point 32 midway between planes 16 and 18. Point 32 serves as a common axis of rotation, about which both lines 20 and 22 oscillate.

Hence, effectively two congruent isosceles triangles A I B moo-s2 and 26-28-32 are formed having a common apex at point 32. The legs of triangles A and b are comprised of lines 20 and 22 which are pivotally affixed to the lower extremity of planes 16 and 18 respectively and, movably affixed to the upper extremity of opposite planes, planes 16 and 18 forming the respective bases.

Therefore, it follows that the legs of such triangles are substantially identical in length and remain the same. However, the angularity of these legs or lines 20 and 22 may be varied due to the incorporation of movable points 26 and 30 within opposite planes. Obviously, increasing the dlstance between adjacent planes or ribs results in a corresponding reduction in bases 24-30 and 26-28 of trlangles A and B as points 26 and 30 travel down their corresponding planes, simultaneously effecting an increase 1n triangle height 11. Conversely, juxtapositioning of planes 16 and 18 increases the length of base 24-30z26-28 and reduces the overall height h.

Structurally, in a preferred embodiment as shown in FIGURE 1, rib members 12a and 12b correspond to planes 16 and 18 and linkages 14a and 1% correspond to lines 20 and 22. In this manner, the extremities of linkages 14a and 1412 are pivotally afiixed between two ribs 12a and 12b at points 34, 36, 38 and 40 corresponding to points 24, 26, 28 and 30 in the geometrical description, thus resulting in a convergence at point 42. Consequently, any modification of triangles 34-40-42 and 36-38-42 brought about by expansion or contraction of rib members 12 relative to one another within the limitation imposed by the systems fixed and movable points will transmit such modifications to the outermost pair of linkages in the system, i.e., if pressure is exerted upon any linkage either in a downwardly direction or away from the rib members, which pressure results in a change in geometry of the hereinabove described triangles, a corresponding change will occur in all such triangles within the system.

All embodiments of the present invention incorporate a series of interconnected ribs having a suitable expansion and contraction system therebetween, as hereinabove described.

Referring now to FIGURE 2, structural rib members 12 support upon their interior surfaces 50 a suitable fabric 52. Fabric 52 extends from rib to rib in the series forming catenary curves 44 (FIGURE 1) therebetween. Further, fabric 52 hasapertures therein which correspond in position to a plurality of fasteners 54 which are afiixed t-o rib 12 and engage and cooperate with a suitably apertured coextensive fabric retainer strip 56. Fabric retainer strip 56 and rib 12 support apertured fabric 52 therebetween as best illustrated in FIGURE 2. Fabric 52 may have afiixed to either surface reinforcing strips of webbing (not shown) which are apertured and coextensive with fabric retainer strip 56.

As hereinabove stated linkages 14 are pivotally attached to the lower portion of each rib member in the series. Pivotal connection is accomplished at these points by employment of a suitable smooth shank stove bolt 60 and lock nut 62. Rib 12 and linkages 14 are suitably apertured to receive bolt 60 therethrough. Smooth operation and proper tolerance of all joints is assured by employment of washers 64 of a fluorocarbon resin material or the like.

Trough member 66 of a suitable material may be employed to receive rounded foot 68 of rib 12. This combination allows the structure to be more easily erected in areas heavy with undergrowth. Further, rounded foot 68 may be replaced by a suitable sphere or wheel (not shown) rotatably mounted thereon.

Linkages 14a and 14b converge at point 42 (as shown in FIGURE 1). As illustrated in FIGURE 3, pivotal movement is achieved and assured at this point by utilization of a smooth shank stove bolt 70 and lock nut 72 combination. Bolt 70 extends through two coaxial apertures in typical linkages 14a and 14b. Washers 74 are employed to assure smooth operation.

FIGURE 4 is illustrative of the split sleeve 80 employed at movable points 38, 40 of FIGURE 1, and which slidably engages rib 12 at its upper extremities (illustrated geometrically as points 26 and in FIGURE 1). Split sleeve 80 permits vertical movement of points 34, 38 in relation to the ribs to which they are affixed. Sleeve 80 has afiixed thereto a suitable bolt 82 and lock nut 84. Bolt 82 receives the upper extremities of converging linkages 14a and 14b. Sleeve 80 may incorporate on its interior walls a suitable bushing 86 (FIGURES 4 and 5) to preclude binding and provide protection against the elements.

As can be readily seen sleeve 80, hence, linkages 14a and 14b are allowed to rise as the shelter is collapsed due to the slidable relationship between sleeve 80 and rib 12. Therefore, each rib may be positioned immediately adjacent to the opposing ribs, thus allowing the entire structure to be closely plicated.

As hereinabove noted, four linkages located at the extremities of the shelter vary in configuration from the remaining linkages. Referring now to FIGURE 6, these are shown to employ spacer 88 which assures proper alignment of the linkages due to the absence of one of the converging linkages at this point.

Referring now to FIGURE 7 wherein as shown another embodiment of the present invention, which embodiment has foldable side walls 706' and 708. This i accomplished as shown by hinging rib members 712 at points 716 and 718 along both sides of the structure. Necessarily, hinge point 716 is higher than hinge point 718 to permit wall 706 to lie fiat upon wall 708 when folded.

This configuration would allow the fabric to be folded and stored within areas 720 and 722, shown in phantom.

Obviously, shelters employing folding legs or walls require structural latches to insure stability of the structure and preclude inadvertent actuation of the folding means.

FIGURES 8 and 9 are illustrative of one such latching mechanism. Latch 724 comprises latch plate 726 and spacer 728 (FIGURE 9) affixed in any suitable manner to interior rib wall 730 in the lower or folding portion 732 of rib 712. Latch plate 726 incorporates an arcuate guideway or slot 734 extending into a circular socket 736, which socket is larger than guideway 734 and is adapted .to receive a suitable cylindrical pawl 738. Pawl 738 is of a diameter commensurate with socket 736 in latch plate 726 and has an annular recess 740 therein, of a diameter which will allow its unrestricted passage within guideway 734. Annular recess 740 forms abutments 742 and 744, one of which is charnfered as at 746. Further, pawl 738 has at the extremity furthest removed from recess 740 an annular spring guide 748.

Pawl 738 is slidably mounted within first and second bores 754 and 756 in a suitable metal or plastic block 758. First bore 754 receives the larger portion 760 of pawl 738, while second bore 756 receives spring guide 748. Bores 754 and 756 are deep enough to allow pawl 738 to move in and out freely. Block 758 may be anchored to folding leg 706 of rib 712 by rivets, screws, etc. Spring guide 748 and second bore 756 contain and support resilient return spring 762.

Latch plate 726 is so constructed as to provide a cam surface or ramp 764, positioned at the entrance to guide way 734.

In operation, locking is accomplished by swivelling folding leg 732 of rib 712, hence, latch plate 726, until ramp 764 engages chamfered abutment 746 in pawl 738, thus camming the pawl into block 758. This movement allows recess 740 to travel within guideway 734 While simultaneously compressing spring 762. The large portion 760 of pawl 738 snaps into socket 736 upon reaching the end of guideway 734. This action is assured by the resiliency of spring 762.

To unlock the mechanism, each pawl 738 may be depressed, thus forcing large portion 760 out of socket 736, thereby allowing the folding portion 732 of rib 712 to swing inward by moving annular recess 740 down guideway 734 until entirely disengaged. With the structure of the present invention in the collapsed form, each each structural rib 712 abuts the adjacent ribs. Adjacent ribs may therefore be employed to depress all pawls simultaneously. Further, two locking mechanisms may be employed at each joint, if desired, by inverting such mechanisms and placing them upon opposite sides.

Leakage of the shelter is in part precluded by the intrinsic catenary curve 44 in fabric 52 between rib members, as best seen in FIGURES 1 and 10. Further, this curvature insures immediate drainage of moisture, thereby impeding mildew of the fabric material.

Either one or both extremities of the shelter may be sealed by an integral end portion 90 (illustrated in FIG- URE 1) of fabric having a suitable opening 92 therein. This opening has a closure member (not shown) which may be integrally attached at one side and sealed by any quick actuating fastener means, such as a zipper.

Further, the shelter may incorporate an integral floor 94 of fabric, which is stored by fastening in various manners to the walls of the shelter.

Another embodiment of the present invention employs- Upon arriving to receive a load, the vehicle operator manually or by various assisting apparatus, rapidly uncovers bed 202 of the vehicle. The covering is plicated and stored within container 200. For a standard military vehicle, this operation requires only 30 seconds. The vehicle may now be loaded by overhead apparatus such as cranes or fork trucks. This structure overcomes a serious operational deficiency in present conventional vehicles, since such vehicles utilizing a military canvas covering require considerable time to unlace and remove the canvas from the bows, store it, and remove and store the wood bows. At times these wood bows are swollen in their receptacles making removal virtually impossible. In addition, the stored canvas and bows materially reduce the area within the vehicle bed which may be used to transport loads. The difliculty is particularly apparent in such a vehicle used to transport combat ready troops, since in such circumstances the canvas cover of the present state-of-the-art is left entirely off, regardless of weather or climatic conditions. Obviously, a cover according to the present invention may be employed in adverse conditions, since removal or employment is merely a matter of seconds under any conditions. After loading has been accomplished, only a few seconds are required to replace the covering as shown in phantom in FIGURE 10. Employing the structure of the invention in this respect results in substantially a pull-over type protective covering for any load. The resultant cover is completely structural and has substantially the same characteristics as a metal body, yet does not occupy any bed space when stored. As is evident, when the shelter is stored it is fully protected from deterioriation by container 200.

FIGURE 11 illustrates another embodiment wherein the structure of the invention is utilized as a portable hanger. In FIGURE 11, the shelter is employed to cover and protect a helicopter 300 of the Iroquois class. Obviously, this configuration functionsin the same manner as the foregoing embodiments. In this particular instance,

two units 310a and 31Gb are employed. Each may have.

a removable container 308 (see inset). at an extremity. Ribs 312 can be rapidly drawn toward the outside extremities, thereby allowing helicopter 300 to take off without prior removal from the shelter. Further, such hanger may employ ventilation windows 320 covered with a suitable insect netting 322 and side wall 306 may be rolled up, as at 324, thus creating opening 326, which may be covered with a suitable insect netting (not shown). Windows 320 and roll-up walls 306 preclude.

hot spots in tunnel 316 and provide ventilation. Windows 320 have a suitable integral storm flap (not shown) to prevent leakage during inclement weather.

Although the operation of shelter 310 (for example) is generally the same as that of the shelter of FIGURE 1, modification has been made in the configuration for functional purposes. Thus, ribs 312 include an additional bowed portion 328 to more effiiciently house the rotor mast and blade assembly 318 of the aircraft. Additionally, this configuration permits the use of a telescoping or segmented track (not shown) at the apex of the bow for cooperation with a movable hoist (not shown) for easy and quick removal or installation ofthe rotor. Shelters 310a, 31% may have a canvas floor 394 if desired. Sill or runners 366 may readily be employed to advantage with this configuration. Bar linkages 314 (corresponding to 14, of FIGURE 1) and sleeve 380 operate as described above.

As herein described the present invention resides in a substantially arcuate structural framework, disposed in a columnar series, which framework is interconnected by a system of two bar linkages, the link-ages so positioned as to permit the structural framework to expand lengthwise in a substantially forty to one ratio. The invention further resides in the novel combination of a fabric with the herein described structural framework, which fabric is attached to the inside of the framework and is protected against deterioration due to abrasion, tears, etc., in the areas generally susceptible thereto by its own framework.

What is claimed is:

1. A readily erectable utility structure, comprising:

(A) support means, said means defined by,

(l) a plurality of structural rib members disposed in a longitudinal interconnected column, said rib members having a substantially inverted trough like shape,

(2) said ribs encompassing bolt means and associated lock means, said bolt means positioned to pivotally receive a force transmitting means,

(3) a portion of said rib means being vertical and having at their upper extremities a sleeve slideable thereon, said sleeve being commensurate in interior configuration to the exterior configuration of said structural rib members,

(4) said sleeve having aflixed on its exterior wall a stud and lock means positioned to receive a force transmitting means,

(5) each said rib member having a pivotal hinge on the vertically disposed portions thereof above the highest point of travel of said sleeve, said pivotal hinges disposed relatively one above the other and operative to permit said vertically disposed portions to be folded inwardly and permit said rib portions and the associated subjacent closure means to fold one upon the other with the closure means enclosed within the folded structure,

and locking meansoperative to retain said rib members in the unfolded position;

(B) means integrally associated with said support means and cooperative therewith to permit expansion and contraction thereof longitudinally relative to one another, said means comprising:

(1) a series of force transmitting means comprising a plurality of converging intersecting structural lineal bar linkages of which there are two of equal length between any pairof rib members,

(2) said linkages being disposed diagonally between said rib members and apertured to receive said bolt and stud means at the extremities thereof,

(3) said linkages pivotally intersecting substantially midway between said ribs,

(4) said pivotal intersection having a bolt means therethrough and secured by a lock nut;

(C) closure means subjacent to and in substantially intimate contact with said support means, said means comprising:

(1) a substantially impervious cover spanning said support means and coextensive therewith,

(2) said cover reinforced upon both sides thereof at points which coincide with said structural rib members,

(3) said reinforced cover supported upon said ribs by retaining means comprising,

(a) a retainer strip coextensive with said rib members and having said cover therebetween,

(b) said retainer strip apertured in a pattern ccLoperative with fasteners affixed to said n s,

(4) said cover defining a wall at either extremity of said structure and having an access means therein.

7 2. An expansible utility structure comprising:

(A) support means comprising a plurality of structural rib members disposed in a longitudinal interconnected column;

(1) said support means each defined by an inverted, U-shaped element, each leg of said U incorpoating a hinge means operative to permit said legs to be folded inwardly, said hinge means being located above the position attained by the force transmission means in its closed relationship, said hinge means bearing a relation ship one to the otherso that when said legs are folded inwardly one will lie in parallel and superior position to the other, said legs forming a protective closure means for one side of the folded structure;

(2) at least some of said hinge means incorporating at latch mechanism operable to structurally join each said rib associated therewith in the unfolded position;

(B) a series of force transmitting means exterior to said ribs comprising a plurality of converging, intersecting, structural bar linkages operative to stabilize and maintain parallel physical relationship between said rib members, and

(C) closure means comprising a flexible cover member substantially coextensive with said support means, said cover member secured to each said rib member on the interior side thereof and operable to pleat inwardly throughout its configuration; whereby said closure member is within and substantially protected by said support members when in their folded, abutting relationship.

3. The structure defined in claim 2 wherein said force transmitting means comprises:

(A) a series of lineal bar linkages wherein;

( 1) there are two said linkages of equal length diagonally biased between and pivotally affixed at the extremities thereof to any pair of said ribs,

(2) said linkages pivotally intersect substantially midway between said ribs,

(3) said linkages are normal to the plane defined by each said rib,

(4) said linkages are operably attached to said ribs on at least two substantially opposed sides thereof,

(5) said linkages, are being compounded into a series, and cooperatively, pivotally attached at their extremities to said structural rib members.

4. A readily erectable utility structure comprising:

(A) support means comprising,

(1) a plurality of structural rib members disposed in a longitudinal interconnected column, said rib members having an inverted trough-like shape defining horizontal and vertical walls;

(a) said vertical walls foldable toward the interior of said structure, said walls comprismg:

(1) a latch mechanism integral with the vertical portion of said ribs and operable to structurally join said ribs in erected position,

(2) said mechanism simultaneously releasable upon plication of said structure,

(2) said ribs encompassing bolt means and associated lock means, said bolt means positioned to pivotally receive a force transmitting means,

(3) a portion of said rib means being vertical and having at their upper extremities a sleeve slideable thereon, said sleeve being commensurate in interior configuration to the exterior configuration of said structural rib members,

(4) said sleeve having afiixed on its exterior wall a stud and lock means positioned to receive a force transmitting means;

(B) means integrally associated with said support means and cooperative therewith to permit expansion and contraction thereof longitudinally relative to one another, said means comprising:

(1) a series of force transmitting means comprising a plurality of converging intersecting structural lineal bar linkages of which there are two of equal length between any pair of rib members,

(2) said linkages being disposed diagonally between said rib members and apertured to receive said bolt and stud means at the extremities thereof,

(3) said linkages pivotally intersecting substantially midway between said ribs,

(4) said pivotal intersection having a bolt means therethrough and secured by a lock nut;

(C) closure means subjacent to and in substantially intimate contact with said support means, said means comprising:

( l) a substantially impervious cover spanning said support means and coextensive therewith,

(2) said cover reinforced upon both sides thereof at points which coincide with said structural rib members,

( 3) said reinforced cover supported upon said ribs by retaining means comprising (a) a retainer strip coextensive with said rib members and having said cover therebetween,

(b) said retainer strip apertured in a pattern cooperative with fasteners afiixed to said ribs;

(D) a removable container member commensurate in shape with said rib structure operative as a self-contained storage means for said structure when plicated; and

(E) said structure incorporating an arcuate tunnel at the apex of said structure along said horizontal wall defined by a bowed portion in said ribs .and operative to give additional vertical height with minimal weight.

References Cited by the Examiner UNITED STATES PATENTS 514,663 2/1894 Pitt 160-136 685,247 10/1910 Borrman. 1,738,219 12/1929 Wickstrurn -4 1,856,658 5/1932 Rummler 135-1 2,334,435 11/1943 Patterson et al. 135-4 2,486,170 10/ 1949 Kavanaugh 13-5-5 2,806,477 9/1957 Fritsche 135-4 2,857,924 10/ 1958 Gibbons et a1. 135-7.1 3,064,667 11/1962 Marino 135-7.1 3,131,705 5/1964 Marino 135-5 HARRISON R. MOSELEY, Primary Examiner. L. I. SANTISI, Assistant Examiner. 

2. AN EXPANSIBLE UTILITY STRUCTURE COMPRISING: (A) SUPPORT MEANS COMPRISING A PLURALITY OF STRUCTURAL RIB MEMBERS DISPOSED IN A LONGITUDINAL INTERCONNECTED COLUMN; (1) SAID SUPPORT MEANS EACH DEFINED BY AN INVERTED, U-SHAPED ELEMENT, EACH LEG OF SAID U INCORPORATING A HINGE MEANS OPERATIVE TO PERMIT SAID LEGS TO BE FOLDED INWARDLY, SAID HINGE MEANS BEING LOCATED ABOVE THE POSITION ATTAINED BY THE FORCE TRANSMISSION MEAN ITS CLOSED RELATIONSHIP, SAID HINGE MEANS BEARING A RELATIONSHIP ONE TO THE OTHER SO THAT WHEN SAID LEGS ARE FOLDED INWARDLY ONE WILL LIE IN PARALLEL AND SUPERIOR POSITION TO THE OTHER SAID LEGS FORMING A PROTECTIVE CLOSURE MEANS FOR ONE SIDE OF THE FOLDED STRUCTURE; (2) AT LEAST SOME OF SAID HINGE MEANS INCORPORATING AT LATCH MECHANISM OPERABLE TO STRUCTURALLY JOIN EACH SAID RIB ASSOCIATED THEREWITH IN THE UNFOLED POSITION; (B) A SERIES OF FORCE TRANSMITTING MEANS EXTERIOR TO SAID RIBSR COMPRISING A PLURALITY OF CONVERGING, INTERSECTING, STRUCTURAL BAR LINKAGES OPERATIVE TO STABILIZE AND MAINTAIN PARALLEL PHYSICAL RELATIONSHIP BETWEEN SAID RIB MEMBERS, AND (C) CLOSURE MEANS COMPRISING A FLEXIBLE COVER MEMBER SUBSTANTIALLY COEXTENSIVE WITH SAID SUPPORT MEANS, SAID COVER MEMBER SECURED TO EACH SAID RIB MEMBER ON THE INTERIOR SIDE THEREOF AND OPERABLE TO PLEAT INWARDLY THROUGHOUT ITS CONFIGURATION; WHEREBY SAID CLOSURE MEMBER IS WITHIN SAID SUBSTANTIALLY PROTECTED BY SAID SUPPORT MEMBERS WHEN IN THEIR FOLDED, ABUTTING RELATIONSHIP. 